1. Field of the Invention
This invention relates to burner valve assemblies and, in particular, to a valve assembly for a single burner industrial boiler wherein a single valve assembly selectively supplies oil and steam to a main burner or to a stand-by burner when the main burner is being repaired or replaced.
2. Description of the Prior Art
In relatively small industrial boiler installations, usually only a single burner is in continuous operation. To ensure complete atomization of the fuel oil, steam is continuously supplied to the burner tip during ignition. The environment in which such burners operate causes the tips thereof to deteriorate and requires replacement on a frequent basis.
Whereas multiple burner boilers can handle replacement of a worn burner by merely retracting the latter while the other burners carry the load, a single burner industrial boiler requires a stand-by burner to carry the load. The stand-by burner is normally not located in the burner environment and is inserted therein only to carry the load while the main burner is being repaired. To accommodate the necessary insertion, lighting and withdrawing of the stand-by burner, a series of conventional shut-off valves are provided which must be operated in a particular sequence by the boiler attendant.
For instance, if the boiler is lit and the worn out tip is repaired or replaced, the attendant inserts the stand-by burner, opens the stand-by steam valve and then the stand-by oil valve so as to effect ignition of the stand-by burner. Then the main oil valve is closed and thereafter the main steam valve is closed. The main burner is then withdrawn for repair. To replace the main burner, a reverse procedure is followed.